Because a user can have multiple services, they need a way to navigate between
them. Normally they can use the ▶ Switcher to do this, except when:
- they first sign in
- they are on a page which isn’t associated with a service (eg user profile) in
which case we can’t use the switcher because it won’t know what the ‘current’
service is
So this commit adds a new page with a (fake) list of services.
